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Does IP telephony suck?

 
 
Klunk
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Posts: n/a
 
      08-16-2008
On Sat, 16 Aug 2008 19:03:08 +0000, Gordon Henderson passed an empty day
by writing:

> In article <48a70e1c$0$2523$(E-Mail Removed)>, Klunk
> <(E-Mail Removed)> wrote:
>>On Sat, 16 Aug 2008 16:20:50 +0000, Gordon Henderson passed an empty day
>>by writing:

>
>>>>I don't know a fantastic amount about this Shoretel thing, but I'd
>>>>love to know what the underlying OS is on it. I would have thought it
>>>>would have been Linux based myself, but that is just a guess.
>>>
>>> I'd be surprised if it was... My experience of the competition is that
>>> they're all very much proprietary and scared pooless of Linux and
>>> Asterisk... (especially in the sub 200 seat scenario)
>>>
>>> (He says, having just had a customer replace their Avaya system with
>>> one of his own PBXs
>>>
>>> Gordon

>>
>>Thanks Gordon. The reason I ask is I am sure that one of the anti-linux
>>brigade will pipe up and blame the OS.

>
> There's nothing an OS can do if another device on the same network
> decides to use it's IP address... And even detecting it on the
> compromised host can be tricky. Things will get really confusing really
> fast unless you can detect it. That's where a good sysadmin comes in...
>
>>What is the general gist of things with all of these IP systems? They
>>are mostly proprietary then?

>
> Yes, mostly. Even some of the ones based on open source solutions keep
> their own internal bits private...
>
> If they build the hardware, write the software then they know *exactly*
> what the system is capable of - especially in terms of number of
> extensions, concurrent calls and so on. That's no bad thing, generally.
>
> A recurring question on some of the asterisk lists is "how big a server
> do I need?" and quite simply unless you've a lot of knowledge about the
> inner "guts" of the box, it's hard to say... Even then, are you using
> stock Linux kernels and distributions or custom?
>
> (And it's something I've spent a lot of time with my own boxes, so I
> know their limitations!)
>
>>Ive just started to 'consider' the phone system in the place after years
>>of working with BT on 'the other side' of the ISDN30's. I'm trying to
>>'get' the concept bit of it - perhaps you can help?

>
> Sure...
>
>>The desktop phones are all RJ45 in & out so I am guessing that (1) they
>>are these things called 'ip phones' and (2) they are getting their power
>>from the RJ45's too.

>
> Not necessarily. They'll get power for sure, but they might not be IP.
> (They might be using the connectors because that makes it easy to work
> with an existing structured cabling in a building)
>
> Or they might be IP, but using their own proprietary protocol. It's all
> about vendor lock-in. Why make your PBX compatible with other
> manufacturers phones? You'll lose money that way, see...
>
> Try googling the phone model number for your systems...
>
> Even some phones from the legacy companies, while advertised as SIP
> compatible, sometimes aren't, so have some weird issues that makes them
> hard to interface with anything other than the same manufacturers
> PBXs...
>
> I don't make phones, so I don't care what gets plugged in to my PBXs,
> although because there are now dozens of independent phone manufacturers
> all making their phones SIP compatible, each with dozens more models, I
> can't test them all, so will only supply a small subset...
>
>>It hooks up to a proprietary server that then attaches to the ISDN30
>>dual fibre. My guess is that the incoming ISDN30 is made up of a number
>>of trunks and DDI's that interface with this unit and are charged as per
>>normal call rates? Or are these likely to be provisioned by a VOIP
>>provider over the ISDN30? I'm a bit confused on the scenarios possible
>>here. (You have to remember - ex-bt, fed on crap, taught on copper,
>>never told anything remotely useful in case we leave).

>
> ISDN30 - at it's simplest is a 2Mb digital data line capable of handling
> up to 30 concurrent calls (channels). You start with 8 and pay BT more
> for each channel you enable. You get the line from BT, and really, here
> we don't care what the underlying technology is - copper or fibre -
> ISDN30 can work over both - we just care about the patch lead from the
> BT box to our PBX. So you have 30 channels (or calls), and any number of
> DDI numbers - 100's if need-be. Having more desk phones than channels is
> quite normal - unless you're in a busy call centre!
>
> (There's a whole field of mathematics to work out the number of channels
> you need vs. the number of people vs. number of minutes on the phone
> each day vs. the probability of running out of lines - look up Erlang)
>
> The 'data' over the ISDN30 is traditional legacy stuff. Each channel is
> a fixed chunk of 64,000 bits/sec. (8000 samples of 8 bits a second)
> Multiply that by 30 and you're a bit short of 2M, but there's space left
> over for signalling (sending the phone number down, etc.)
>
>
>>I've heard the phrased 'hosted' a great deal and I'm guessing at a
>>simple level this is the kind of thing that Sipgate offer where they
>>have their own VOIP server and the EU simply connects into it via a
>>WAN/DSL connection?

>
> At it's simplest level, yes - although Sipgate are really doing it on a
> single-line basis - no "desk to desk" facilities.
>
> A lot of people really are pushing hosted solutions (probably becuae
> they've spent a lot of money on them The legacy (BT) world equivalent
> is "Centrex", but although I run such a service myself, I don't really
> push it. Not convinced it's good for anything more than a small office
> of 1-4 people, or lots of distributed small offices....
>
>> I stretch my guess to assume that with the in-house Shoretel,
>>that this becomes a PBX 'host' if you like and is therefore not a hosted
>>solution?

>
> Yes. ISDN30 in, phones on desks out with the Shoretel PBX acting as a
> big switch plumbing it all together. Maybe with extra features like
> voicemail, call recording and so on. That's what a PBX is.
>
>>Any of the VOIP gurus who want to correct any of that to reality will
>>receive a virtual cup of tea

>
> Heh..
>
>
> VoIP is out there and it works, and it works well - given the
> limitations of the UK broadband network - however I think there's still
> a lot of mis-information out there (and some cowboys )-: I've met
> people who tell me that VoIP is rubbish, but then they're paying 9.99
> for a rubbish ISP... You get what you pay for! And there's a lot of
> "legacy" about.... The crippling contracts that the dinosaur
> manufacturers sign their clients into mean that it's almost impossible
> for them to break out if/when they do want to go VoIP or their existing
> vendor will charge them an arm and 2 legs to enable a *single* SIP
> interface on the PBX to enable a home worker, or charge per channel to
> connect 2 PBXs together to link offices up... There's 60 years of FUD to
> try to unravel before VoIP will become more readily acceptable...
>
>
> Gordon


Thanks for taking the time to run through that with me Gordon. It's the
first USENET post that I've cut, pasted and saved for a number of years.

Being ex-BT the bit that bewildered me was this dual fibre thing only
delivering a 2m link when I know we used to knock the same thing down a
couple of pairs of copper. I can't see the benefit in using the fibre in
the first place when you factor in the cost! One of the guys in the place
was saying that they tried to get their DSL down the fibre too and BT
laughed at them, telling them it could not be done. I'm sure that a fibre
link is plenty capable of speed - oddles of it in fact. My best guess is
that there is no 'product' that matches what the company I am working for
wants.

I get your point about the reliability of VOIP. Clearly there is going to
be a big difference with good hardware, a fibre ISDN 30 and dedicated
equipment. Much more than a DSL line, a PAP2 and a wonky PSU

I've got the bug over this whole thing. My interest in telecoms goes way
back and it captivates me. I'm going to have a 'play' with Asterisk. I'm
a Linux bug anyway, so I don't have a steep learning curve. It's going to
come down to basic concepts. I've read that there are hardware issues
with PCI latency, but I don't know how old the article was. Other than
the Box Gordon, what am I going to need to set up a little 'test'
Asterisk system? Say I have 2 X PSTN on the wall + 2 X Sipgate and wanted
to put in 5 extensions. I guess I'm going to need some 'compatible'
phones - hows and what's I am not clear on. I guess I will also need some
form of card to convert the incoming PSTN. How this will all bolt
together, and be 'cheap enough' so that her indoors will let me play -
whilst giving me a useful 'primer' is yet to be seen.

\~~~~~/#
\ / #
\_/#
-------- Your tea, Sir.


--
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http://www.velocityreviews.com/forums/(E-Mail Removed)
 
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Gordon Henderson
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Posts: n/a
 
      08-16-2008
In article <48a72e8f$0$2928$(E-Mail Removed)>,
Klunk <(E-Mail Removed)> wrote:

>Thanks for taking the time to run through that with me Gordon. It's the
>first USENET post that I've cut, pasted and saved for a number of years.
>
>Being ex-BT the bit that bewildered me was this dual fibre thing only
>delivering a 2m link when I know we used to knock the same thing down a
>couple of pairs of copper. I can't see the benefit in using the fibre in
>the first place when you factor in the cost! One of the guys in the place
>was saying that they tried to get their DSL down the fibre too and BT
>laughed at them, telling them it could not be done. I'm sure that a fibre
>link is plenty capable of speed - oddles of it in fact. My best guess is
>that there is no 'product' that matches what the company I am working for
>wants.


BT want to put fibre everywhere, but tehy do have some odd rules - it's
probably to do with the competition rules set by Ofcom/whatever. It
wouldn't surprise me if they were using less than 1% of the capacity of
all the fibre they've laid....

>I get your point about the reliability of VOIP. Clearly there is going to
>be a big difference with good hardware, a fibre ISDN 30 and dedicated
>equipment. Much more than a DSL line, a PAP2 and a wonky PSU
>
>I've got the bug over this whole thing. My interest in telecoms goes way
>back and it captivates me. I'm going to have a 'play' with Asterisk. I'm
>a Linux bug anyway, so I don't have a steep learning curve. It's going to
>come down to basic concepts. I've read that there are hardware issues
>with PCI latency, but I don't know how old the article was. Other than
>the Box Gordon, what am I going to need to set up a little 'test'
>Asterisk system? Say I have 2 X PSTN on the wall + 2 X Sipgate and wanted
>to put in 5 extensions. I guess I'm going to need some 'compatible'
>phones - hows and what's I am not clear on. I guess I will also need some
>form of card to convert the incoming PSTN. How this will all bolt
>together, and be 'cheap enough' so that her indoors will let me play -
>whilst giving me a useful 'primer' is yet to be seen.


Look for trixbox or pbx in a flash. They're mostly "canned" versions
of Asterisk + Linux, but might get you going. Failing that, see if your
Linux distribution has packages, and if all-else fails, try
www.asterisk.org and compile it from source...

Hardware wise, look for a TDM400 card with 2 x FXO modules. (You
might want to try the OpenVox clone cards as they are cheaper). I use
http://www.voipon.co.uk/ for most of this stuff. Stick an FXS module
on it too to connect up a local anlogue phone (cheaper than an ATA but
you'll not get much change from 220 for the card + 3 modules)

(US terminology - FXO's connect to the "Central Office" ie the Telephone
Exchange, FXS connect to Stations - ie phones)

If you just had one line, then you might find an X100p card (or clone
card) on eBay for 20 or less though. I don't think it's good to have 2
of them in a PC though.

You won't have PCI latency issues on a relatively new motherboard, but
the TDM card prefers to have an IRQ all of it's own. (Although I'm told
the newer TDM410 boards are much better in this respect) I haven't done
an analogue install for a month or so, so not looked at the newer card
yet, but I have an openVox card I'm experimenting with...

You might also want to download "the starfish book" and read it - Search
for "Asterisk - the future of telephony" - it's in PDF format now.

Cheap & basic phones are Grandstream BT200's, but the display is numeric
only. They are in the "fisher price" range, but I've deployed quite a
few of them with good results.

Have fun!

Gordon
 
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Allan Gould
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Posts: n/a
 
      08-16-2008
Arse Cork OK wrote:
> On Sat, 16 Aug 2008 16:24:11 +0100, Chris Davies wrote:
>
>> Klunk <(E-Mail Removed)> wrote:
>>> Always been a fan of Voip. Use it at home myself via Sipgate.

>> Good story. Shame you multiposted instead of crossposting. Chris


[snip]

> I think you can take that to mean 'F*ck off' in case you
> were wondering


The spiel of expletives and invective by "Arse Cork OK" was more
offensive than Chris' claim of multiposting or crossposting, IMHO.
 
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Klunk
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      08-17-2008
On Sat, 16 Aug 2008 20:30:56 +0000, Gordon Henderson passed an empty day
by writing:

> In article <48a72e8f$0$2928$(E-Mail Removed)>, Klunk
> <(E-Mail Removed)> wrote:
>
>>Thanks for taking the time to run through that with me Gordon. It's the
>>first USENET post that I've cut, pasted and saved for a number of years.
>>
>>Being ex-BT the bit that bewildered me was this dual fibre thing only
>>delivering a 2m link when I know we used to knock the same thing down a
>>couple of pairs of copper. I can't see the benefit in using the fibre in
>>the first place when you factor in the cost! One of the guys in the
>>place was saying that they tried to get their DSL down the fibre too and
>>BT laughed at them, telling them it could not be done. I'm sure that a
>>fibre link is plenty capable of speed - oddles of it in fact. My best
>>guess is that there is no 'product' that matches what the company I am
>>working for wants.

>
> BT want to put fibre everywhere, but tehy do have some odd rules - it's
> probably to do with the competition rules set by Ofcom/whatever. It
> wouldn't surprise me if they were using less than 1% of the capacity of
> all the fibre they've laid....
>
>>I get your point about the reliability of VOIP. Clearly there is going
>>to be a big difference with good hardware, a fibre ISDN 30 and dedicated
>>equipment. Much more than a DSL line, a PAP2 and a wonky PSU
>>
>>I've got the bug over this whole thing. My interest in telecoms goes way
>>back and it captivates me. I'm going to have a 'play' with Asterisk. I'm
>>a Linux bug anyway, so I don't have a steep learning curve. It's going
>>to come down to basic concepts. I've read that there are hardware issues
>>with PCI latency, but I don't know how old the article was. Other than
>>the Box Gordon, what am I going to need to set up a little 'test'
>>Asterisk system? Say I have 2 X PSTN on the wall + 2 X Sipgate and
>>wanted to put in 5 extensions. I guess I'm going to need some
>>'compatible' phones - hows and what's I am not clear on. I guess I will
>>also need some form of card to convert the incoming PSTN. How this will
>>all bolt together, and be 'cheap enough' so that her indoors will let me
>>play - whilst giving me a useful 'primer' is yet to be seen.

>
> Look for trixbox or pbx in a flash. They're mostly "canned" versions of
> Asterisk + Linux, but might get you going. Failing that, see if your
> Linux distribution has packages, and if all-else fails, try
> www.asterisk.org and compile it from source...
>
> Hardware wise, look for a TDM400 card with 2 x FXO modules. (You might
> want to try the OpenVox clone cards as they are cheaper). I use
> http://www.voipon.co.uk/ for most of this stuff. Stick an FXS module on
> it too to connect up a local anlogue phone (cheaper than an ATA but
> you'll not get much change from 220 for the card + 3 modules)
>
> (US terminology - FXO's connect to the "Central Office" ie the Telephone
> Exchange, FXS connect to Stations - ie phones)
>
> If you just had one line, then you might find an X100p card (or clone
> card) on eBay for 20 or less though. I don't think it's good to have 2
> of them in a PC though.
>
> You won't have PCI latency issues on a relatively new motherboard, but
> the TDM card prefers to have an IRQ all of it's own. (Although I'm told
> the newer TDM410 boards are much better in this respect) I haven't done
> an analogue install for a month or so, so not looked at the newer card
> yet, but I have an openVox card I'm experimenting with...
>
> You might also want to download "the starfish book" and read it - Search
> for "Asterisk - the future of telephony" - it's in PDF format now.
>
> Cheap & basic phones are Grandstream BT200's, but the display is numeric
> only. They are in the "fisher price" range, but I've deployed quite a
> few of them with good results.
>
> Have fun!
>
> Gordon


Thanks Gordon - another cut and paste and plenty to play with
Thank you for your time.



--
powered by Linux - bastardized by Window$ -
(E-Mail Removed)
 
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mr deo
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Posts: n/a
 
      08-17-2008

"Klunk" <(E-Mail Removed)> wrote in message
news:48a6d297$0$26082$(E-Mail Removed)...
> Always been a fan of Voip. Use it at home myself via Sipgate.
>
> I did have to laugh how the IT business I work at was brought to its
> knees by an IP telephony outage this week.
>
> A small call centre with about 50 staff running a Shoretel system ground
> to a halt when the phone system fell over. They blamed the BT ISDN 30
> link, but that was still up and OK. They blamed the licencing running
> out, but that was not it. No, some guy had plugged a laptop with a fixed
> IP address into a RJ45 jack. Sadly, the fixed IP address only matched the
> Shoretel server and confused it.
>
> To compound the matter, someone then tried to restart the server and it
> locked up in sheer confusion.
>
> 2 days later and the phones are back on, but how fantastic is that to
> have an IT call centre brought to its knees with such a simple outage.
>
> Best of all, there was not even so much as a PSTN phone in the place to
> plug into the DSL/FAX line to get out of the shite. Magic.
>
>
>
> --
> powered by Linux - bastardized by Window$ -
> (E-Mail Removed)


I have seen networks do this before, I dont think it's a IP Telephony flaw,
as W2K, Linux, and many routers can all fall over when you get 2 peices of
hardware trying to claim the same IP..
Time to fire the tech who was in charge, and the guy who plugg'd in the
lappy.


 
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Stephen
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Posts: n/a
 
      08-18-2008
On Sun, 17 Aug 2008 21:10:22 GMT, "mr deo"
<(E-Mail Removed)> wrote:

>
>"Klunk" <(E-Mail Removed)> wrote in message
>news:48a6d297$0$26082$(E-Mail Removed).. .
>> Always been a fan of Voip. Use it at home myself via Sipgate.
>>
>> I did have to laugh how the IT business I work at was brought to its
>> knees by an IP telephony outage this week.
>>
>> A small call centre with about 50 staff running a Shoretel system ground
>> to a halt when the phone system fell over. They blamed the BT ISDN 30
>> link, but that was still up and OK. They blamed the licencing running
>> out, but that was not it. No, some guy had plugged a laptop with a fixed
>> IP address into a RJ45 jack. Sadly, the fixed IP address only matched the
>> Shoretel server and confused it.
>>
>> To compound the matter, someone then tried to restart the server and it
>> locked up in sheer confusion.
>>
>> 2 days later and the phones are back on, but how fantastic is that to
>> have an IT call centre brought to its knees with such a simple outage.
>>
>> Best of all, there was not even so much as a PSTN phone in the place to
>> plug into the DSL/FAX line to get out of the shite. Magic.
>>
>>
>>
>> --
>> powered by Linux - bastardized by Window$ -
>> (E-Mail Removed)

>
>I have seen networks do this before, I dont think it's a IP Telephony flaw,
>as W2K, Linux, and many routers can all fall over when you get 2 peices of
>hardware trying to claim the same IP..
>Time to fire the tech who was in charge, and the guy who plugg'd in the
>lappy.


no - back end servers should be on the other side of a router where
they are less likely to have user address conflicts.

i blame the designer - or whoever cut the budget.....
>

--
Regards

(E-Mail Removed) - replace xyz with ntl
 
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Chris Davies
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Posts: n/a
 
      08-19-2008
mr deo <(E-Mail Removed)> wrote:
> W2K, Linux, and many routers can all fall over when you get 2 peices of
> hardware trying to claim the same IP..


I'm pretty sure I've seen Windows boxes complain when something else
answers an ARP request for their own IP address. Good idea IMO (for lots
of reasons).

Chris
 
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